Cholecystoduodenal fistula (CDF) is an uncommon condition characterized by an abnormal connection between the gallbladder and the duodenum, often linked to cholelithiasis. It typically presents with nonspecific symptoms such as abdominal pain and jaundice but can occasionally result in severe upper gastrointestinal (GI) bleeding. This report describes the case of a 94-year-old female who presented with hypovolemic shock and multiple episodes of hematemesis. An upper GI endoscopy confirmed a CDF with active hemorrhage. Due to her comorbidities and poor performance status, an endoscopic approach using hemostatic spray was chosen, resulting in a favorable clinical outcome. The development of CDF is typically a result of chronic gallbladder inflammation and cholecystitis, leading to adhesion and erosion into the duodenum. Diagnosis involves imaging and endoscopic techniques, and management varies based on the patient's condition, encompassing surgical, endoscopic, or conservative approaches. This case highlights the necessity of considering CDF in the differential diagnosis of upper GI bleeding, especially in patients with recurrent cholecystitis, and emphasizes the importance of individualized management strategies. It is notable for the use of a minimally invasive endoscopic technique to manage a high-risk patient, highlighting an alternative to surgical intervention.